Why is it dark in space? Causes of the phenomenon

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Why is it dark in space? Causes of the phenomenon
Why is it dark in space? Causes of the phenomenon
Anonim

One of the astronomical mysteries over which scientists have been arguing for millennia is why it is always dark in space.

The well-known specialist Thomas Diggs, whose years of life fell on the 16th century, argued that the Universe is immortal and infinite, there are many stars in its spaces, new ones appear regularly. But if you believe this theory, then at any time of the day the sky should be dazzlingly bright from their light. But in reality, everything is quite the opposite: during the day everything is illuminated by one sun, and at night the sky is dark, with points of stars barely visible to the naked eye. Why is this happening?

Why can't the sun light up space?

Star under the name of the Sun

Anyone can see the sun, which during the day illuminates the entire sky and the surrounding objects of reality. But if we could just climb a few thousand kilometers up, we would notice an increasingly thickening darkness and brightflashes of distant stars. And here a completely logical question arises: if the Sun shines, why is it dark in space?

Experienced physicists have long found the answer to this question. The whole secret is that the Earth is surrounded by an atmosphere filled with oxygen molecules. They reflect the sunlight directed in their direction, acting like billions of miniature mirrors. This effect gives the impression of a blue sky overhead.

There is too little oxygen in outer space to reflect light from even the closest source, so no matter how strong the Sun shines, it will be surrounded by a frightening black haze.

Olbers paradox

Wilhelm Olbers

Diggs was thinking about the sky, covered with an infinite number of stars. He was confident in his theory, but one thing confused him: if there are many stars in the sky that never end, then it must be very bright at any time of the day or night. In any place where the human eye falls, there should be another star, but everything happens exactly the opposite. He did not understand this.

After his death, this was temporarily forgotten. In the 19th century, during the lifetime of the astronomer Wilhelm Olbers, this riddle was again remembered. He was so excited about this problem that the question of why it is dark in space if the stars are shining was called the Olbers paradox. He found several possible answers to this question, but in the end settled on the version that spoke of dust in outer space, which covers the light of most stars in a dense cloud, so they are not visible from the surface.Earth.

After the death of the astronomer, scientists learned that powerful radiations of energy depart from the surface of stars, which can heat the temperature of the surrounding dust to such an extent that it begins to glow. That is, clouds cannot interfere with starlight. Olbers' paradox got a second life.

Space researchers tried to study it, offering other answers to the burning question. The most popular was the version about the dependence of starlight on the location of its carrier: the farther the star, the weaker the radiation from it. This option was not continued, since there are an infinite number of stars, there should be enough light from them.

But every night the sky gets darker. Another generation of astronomers proved that Diggs and Olbers were wrong in their assumptions. Edward Garrison, a well-known researcher of space phenomena, became the creator of the book "Darkness of the Night: The Mystery of the Universe". He laid in it another theory, which is followed to this day. According to her, there are not enough stars to constantly illuminate the night sky. In fact, there are a limited number of them, they tend to end, like our Universe.

Infinite stars - myth or reality?

Stars in space

There is a mathematical theorem: if you look at a substance with a non-zero density, which is in boundless outer space, then in any case it can be seen through a certain distance. In the case when the cosmos is infinite and filled with stars, the gaze directed toany direction, must see another star.

From the same theorem, we can conclude that the light from the stars will be directed in all directions and reach the earth's surface, regardless of their location. That is, a boundless universe filled with constantly sparkling stars would have a bright sky at any time of the day.

Role of the Big Bang

Big Bang

At first glance, it seems that such a theory is not confirmed in real life. A person cannot see all the galaxies from the earth's surface, even with the help of special devices. To confirm their existence, he had to go into space, moving away from his home planet at a certain distance.

But scientists have their own opinion, which is based on the Big Bang - it was after it that the formation of planets began. Yes, there are many galaxies and individual stars outside the Earth, but their light has not yet reached us, since not much time has passed since the explosion from an astronomical point of view. It follows from this that the process of the development of the Universe has not yet been completed, and cosmic processes can affect the distance between the planets, delaying the moment when their light will be visible from the earth's surface.

Astrophysicists believe that the reason for the Big Bang is that the Universe had a higher temperature and density in the past. After the explosion, the indicators began to fall, which allowed the formation of stars and galaxies to start, so today they are not surprised by the fact that it is dark and cold in space.

Telescope as a way to see the past of stars

One of the simplest telescopes

Any observer on the earth's surface can see starlight. But few people know that a star sent us this light in the distant past.

For example, you can remember Andromeda. If you go to her from Earth, then the journey will take 2,300,000 light years. This means that the light that it emits reaches our planet during this period of time. That is, we see this galaxy as it was more than two million years ago. And if suddenly a catastrophe occurs in outer space that destroys it, then we will find out about it after the same period of time. By the way, the light of the Sun reaches the surface of the earth 8 minutes after the start of the journey.

The modern process of technological development has affected telescopes, allowing them to be more powerful than the first copies. Thanks to this property, people see the light from the stars, which began to go to the Earth almost tens of billions of years ago. If we recall the age of the Universe, which is 15 billion years, then the figure makes an indelible impression.

True color of the cosmos

Only a narrow circle of specialists knows that with the help of electromagnetic devices you can see completely different shades of space. All celestial bodies and astronomical phenomena, including supernova explosions and moments of collision of clouds consisting of gas and dust, emit bright waves that can be picked up by special devices. Our eyes are not designed for such actions, so people wonder why it is dark in space.

Ifgive people the ability to see the electromagnetic background of the environment, they would see that even the dark sky is very bright and rich in color - in fact, there is no black space anywhere. The paradox is that in this case, humanity would not have had a desire to explore outer space, and modern knowledge about planets and distant galaxies would have remained unexplored.

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